All works fine & the installation went smooth, however when I set up a sub domain I get a license error

works  with no license error>>   http://mysite.com/cast

does not work, license error>>   radio.mysite.com

any ideas ??

thanks in advanced!  

Yup, the problem is mostly what you'd expect -- your license is issued to mysite.com, so that'll work with no license error.  It's not issued to radio.mysite.com, so that'll give you a license error since radio.mysite.com is not mysite.com.